Effectiveness of reactive power sources for power system performance enhancement

Increased load demand can severely deteriorate the performance of a power system. Building new generation and transmission facilities are not easy due to economic and environmental constraints. As a result, power systems are operated close to their limits. The probability of blackouts during contingencies is high when the power system is operating under stressed conditions. The power system should be operated in such a way that the voltage limits and thermal limits of equipments are not violated. In addition, the possibilities of voltage collapse and voltage stability problems must be considered. -- Reactive power planning is an important aspect of power system planning and operation when a power system is highly stressed. The most important requirement of a power system for maintaining desired performance is the existence of a sufficient amount of reactive power reserve in the proper location of the power system. Installing devices that supply reactive power (like capacitors, static VAR compensator etc.) can enable the power system to be operated closer to their limits and thus make it possible to get the ‘best’ from the existing resources. Optimal Power Flow (OPF) is used to optimize the power system performance. -- This thesis shows the effectiveness of reactive power supply for the performance enhancement of power systems. The problems considered are related to maintaining acceptable voltage profile and ensuring adequate voltage stability margin during a contingency is within an acceptable level. Case studies are presented throughout the thesis to show the effectiveness of reactive power supply. These techniques are well known when considering a specific problem individually. However, there remains a major challenge to determine the best locations and controls for reactive power discuses to provide maximum benefit to the power system as a while during normal operation as well as during contingencies